Motivational interviewing (MI) is a client-centered, albeit directive, method for enhancing intrinsic motivation and strengthening commitment for change through exploring and resolving ambivalence. This article presents the core principles of MI and describes its underlying spirit, which consists of attitudes of collaboration, evocation, and respect for client autonomy. Key process markers indicating the use of MI, including ambivalence, resistance, and change talk, are described. A case example is used to illustrate the application of MI-specific core skills (i.e., rolling with resistance, expanding change talk, and developing discrepancy) in response to each of these process markers, and the theoretical basis for the demonstrated interventions is discussed.